A photocurable inner liner hose and its preparation method

Abstract

This invention provides a photocurable inner-lined flexible tube and its preparation method. The preparation method involves sequentially combining a translucent inner film, a photocurable glass fiber resin layer, and an anti-UV outer film from the inside out to obtain the photocurable inner-lined flexible tube. The photocurable glass fiber resin layer is obtained by brushing the photocurable resin onto both sides of glass fiber cloth, with the same amount brushed on both sides, and the total amount brushed is 42%-48% of the weight of the glass fiber cloth. The photocurable resin, by weight, comprises the following raw material components: 100 parts epoxy acrylate, 12-15 parts porous microspheres, 35-45 parts diluent, 5-9 parts UV photoinitiator, 2-4 parts thickener, and 0.8-2 parts defoamer. This invention can avoid volume shrinkage of the photocurable glass fiber resin layer during the photocuring process, ensuring excellent mechanical properties of the resulting photocurable inner-lined flexible tube.

Description

Technical Field

[0001] This invention belongs to the field of photocurable hose technology, specifically relating to a photocurable inner liner hose and its preparation method. Background Technology

[0002] The aging and damage of underground drainage pipes is a serious problem for cities. Traditional excavation repairs are time-consuming, costly, and inconvenient. Existing trenchless repair methods involve inserting a UV-cured flexible liner into the damaged pipe. Inflation causes the liner to adhere to the inner wall of the damaged pipe. UV light then hardens the liner, creating a rigid "pipe-in-pipe" structure. This allows the damaged pipe to be repaired in situ without excavation and returned to normal use.

[0003] Existing UV-curable lined hoses consist of an inner membrane, a resin-impregnated glass fiber layer, and an outer membrane. The inner membrane is a high-transmittance composite membrane, and the outer membrane is an anti-UV composite membrane. The commonly used resin-impregnated glass fiber layer mainly includes epoxy acrylate, UV initiator, chopped glass fiber, and other functional components such as diluents, thickeners, and defoamers.

[0004] However, during the photocuring process, the liquid resin (epoxy acrylate) in the glass fiber layer of the impregnated resin is transformed into a solid state by ultraviolet light irradiation, which reduces the intermolecular distance. This microscopic change causes the glass fiber layer of the impregnated resin to shrink in volume on a macroscopic level. This volume shrinkage can lead to stress or microcracks inside the UV-cured inner lining hose, thereby affecting its overall mechanical properties. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a photocurable inner liner hose and its preparation method, which avoids volume shrinkage of the photocurable glass fiber resin layer during the photocuring process and ensures that the photocurable inner liner hose has excellent mechanical properties.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a photocurable inner liner hose, wherein a light-transmitting inner membrane, a photocurable glass fiber resin layer, and an anti-ultraviolet outer membrane are sequentially combined from the inside out to obtain a photocurable inner liner hose. The photocurable glass fiber resin layer is made by brushing photocurable resin onto both sides of glass fiber cloth, with the same amount of resin on both sides, and the total amount of resin is 42%-48% of the weight of the glass fiber cloth. The photocurable resin, by weight, comprises the following raw material components: 100 parts epoxy acrylate, 12-15 parts porous microspheres, 35-45 parts diluent, 5-9 parts ultraviolet photoinitiator, 2-4 parts thickener, and 0.8-2 parts defoamer.

[0007] Furthermore, the fiberglass cloth is a biaxial fabric.

[0008] Furthermore, the method for preparing the porous microspheres is as follows:

[0009] A1. Dissolve 20 mL of glycidyl methacrylate, 15 mL of ethylene glycol dimethacrylate, 20 mL of toluene, 40 mL of n-octanol and 0.8 g of benzoyl peroxide by sonication. Add 500 mL of an aqueous solution containing 0.2% polyvinyl alcohol and 0.05% sodium dodecyl sulfate, and sonicate to completely emulsify the oil phase to obtain an emulsion.

[0010] A2. Disperse 100 mL of seed microsphere slurry in 500 mL of an aqueous solution containing 1% polyvinyl alcohol and 0.1% sodium dodecyl sulfate to obtain a seed dispersion.

[0011] A3. The emulsion obtained in A1 is added dropwise to the seed dispersion obtained in A2 at a rate of 10 mL / min. The temperature is controlled at 35℃, and the mixture is allowed to swell for 12 hours. Nitrogen gas is then introduced for 20 minutes, and the mixture is stirred at a constant temperature of 70℃ for 24 hours to obtain porous microspheres.

[0012] Furthermore, in A2, the preparation method of the seed microsphere slurry is as follows:

[0013] Mix 50 mL of glycidyl methacrylate, 0.25 g of azobisisobutyronitrile, 12.5 g of polyvinylpyrrolidone, and 500 mL of anhydrous ethanol, sonicate for 10 min to fully dissolve into a homogeneous solution, purge with nitrogen to remove oxygen, and rotary evaporate in a 70 °C constant temperature water bath for 12 h. After settling, discard the supernatant, wash the precipitate three times with anhydrous ethanol, and then wash three times with water. Disperse the resulting substance at 0.1 g / mL in an 8% polyvinyl alcohol aqueous solution to obtain the seed microsphere slurry.

[0014] Furthermore, the epoxy acrylate includes phenolic epoxy acrylate and / or bisphenol A epoxy acrylate.

[0015] Furthermore, the diluent includes 1,6-hexanediol diacrylate and / or trimethylolpropane triacrylate.

[0016] Furthermore, the ultraviolet photoinitiator includes 1-hydroxycyclohexylbenzophenone and / or 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0017] Furthermore, the thickener is fumed SiO2.

[0018] Furthermore, the defoamer is polydimethylsiloxane and / or polyether.

[0019] Secondly, the present invention provides a photocurable inner liner hose, which is prepared by the above-described preparation method.

[0020] This application has the following beneficial effects:

[0021] 1. This invention uses fiberglass cloth, which provides better structural support. It not only increases the adsorption capacity of the photocurable resin but also provides a robust framework for the resin during UV curing, thereby enhancing the overall strength and mechanical properties of the inner lining hose. The introduction of porous microspheres forms a porous structure within the photocurable resin. These microspheres act as spacers, mitigating shrinkage stress caused by curing to some extent, thus reducing the overall volume shrinkage rate and preventing stress or microcracks inside the inner lining hose, avoiding negative impacts on its mechanical properties. Furthermore, the fiberglass cloth provides a stable two-dimensional mesh structure, and the porous microspheres homogeneously fill these meshes, forming a composite material layer that is both strong and elastic. The two work synergistically to reduce the volume shrinkage of the photocurable resin during UV curing, preventing wrinkles on the surface of the inner lining hose that affect its flatness, and improving the mechanical properties (flexural strength, tensile strength) of the inner lining hose.

[0022] 2. Fiberglass cloth is composed of continuous fibers, which are more regular and uniform than chopped fiberglass. This allows for more even stress distribution, improves overall structural integrity, effectively reduces material porosity, and minimizes microscopic defects caused by bubble formation. This is crucial for improving the mechanical properties of the final inner-lined hose. In particular, with a lining arrangement of ±45°, the biaxial fabric can provide excellent bundling during the forming process, which is essential for improving interlayer performance and providing better structural integrity and mechanical properties when manufacturing inner-lined hoses.

[0023] 3. Porous microspheres with porous structure and cross-linking properties are prepared by copolymerization of monomers such as glycidyl methacrylate and ethylene glycol dimethacrylate. On the one hand, during photocuring, the resin volume shrinks due to the polymerization reaction. The porous structure of the microspheres can act as a buffer zone, absorbing and compensating for the volume change caused by the polymerization reaction by providing spatial buffer, thereby reducing the overall volume shrinkage rate and enhancing the mechanical properties of the inner lining hose. On the other hand, during photocuring, the cross-linking structure can restrict the movement of molecular chains. Through structural restriction, the volume shrinkage caused by the proximity of molecular chains is reduced, further enhancing the mechanical properties of the inner lining hose. Attached Figure Description

[0024] Figure 1 A comparative trend diagram of the bending strength of the light-cured inner lining hoses prepared in Examples 1-6 and Comparative Examples 1-6 of the present invention;

[0025] Figure 2 A comparison trend of the tensile strength of the photocurable inner lining hoses prepared in Examples 1-6 and Comparative Examples 1-6 of the present invention. Detailed Implementation

[0026] The present application will be further described in detail below with reference to the embodiments.

[0027] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application are all commercially available.

[0028] Example 1: A method for preparing a photocurable inner-lined flexible tube, comprising sequentially bonding a translucent inner film, a photocurable glass fiber resin layer, and an anti-UV outer film from the inside out to obtain the photocurable inner-lined flexible tube. This process is existing technology. First, the materials for each layer, namely the translucent inner film, the photocurable glass fiber resin layer, and the anti-UV outer film, need to be prepared. These materials need to be precisely cut to conform to the shape and size of the final product. Then, the photocurable glass fiber resin layer is placed between the translucent inner film and the anti-UV outer film, ensuring that the three are tightly bonded. A press or manual pressure can be used to help the materials adhere tightly. Then, the bonded material is rolled into a tube shape, and the edges are sealed using adhesives or heat welding to ensure the stability and sealing of the tubular structure. The translucent inner film is made of polyethylene film, purchased from Changqing Plastics Factory, Lanshan District, Linyi City; the anti-UV outer film is made of polytetrafluoroethylene film, purchased from Shenzhen Deli New Materials Co., Ltd.

[0029] The light-curing glass fiber resin layer is made by brushing light-curing resin onto both sides of glass fiber cloth, with the same amount of resin on both sides, and the total amount of resin is 45% of the weight of the glass fiber cloth.

[0030] The fiberglass cloth was purchased from Guangdong Bohao Composite Materials Co., Ltd., specifically the biaxial product EKB600(+-45)-1270.

[0031] The photocurable resin, by weight, comprises the following raw material components: 100 parts epoxy acrylate, 14 parts porous microspheres, 40 parts diluent, 7 parts UV photoinitiator, 3 parts thickener, and 1.5 parts defoamer. The preparation process is simple; all raw material components are simply added to a stirrer and stirred until homogeneous at room temperature. The epoxy acrylate includes phenolic epoxy acrylate (DSM) and bisphenol A epoxy acrylate (DSM) E-10, with a mass ratio of 3:1. The diluent is 1,6-hexanediol diacrylate (Covestro). The UV photoinitiator is 1-hydroxycyclohexyl benzophenone. The thickener is fumed SiO2. The defoamer is polydimethylsiloxane.

[0032] The preparation method of porous microspheres is as follows:

[0033] A1. Dissolve 20 mL of glycidyl methacrylate, 15 mL of ethylene glycol dimethacrylate, 20 mL of toluene, 40 mL of n-octanol and 0.8 g of benzoyl peroxide by sonication. Add 500 mL of an aqueous solution containing 0.2% polyvinyl alcohol and 0.05% sodium dodecyl sulfate, and sonicate to completely emulsify the oil phase to obtain an emulsion.

[0034] A2. Disperse 100 mL of seed microsphere slurry in 500 mL of an aqueous solution containing 1% polyvinyl alcohol and 0.1% sodium dodecyl sulfate to obtain a seed dispersion.

[0035] A3. The emulsion obtained in A1 is added dropwise to the seed dispersion obtained in A2 at a rate of 10 mL / min. The temperature is controlled at 35℃, and the mixture is allowed to swell for 12 hours. Nitrogen gas is then introduced for 20 minutes, and the mixture is stirred at a constant temperature of 70℃ for 24 hours to obtain porous microspheres.

[0036] In A2, the preparation method of seed microsphere slurry is as follows:

[0037] Mix 50 mL of glycidyl methacrylate, 0.25 g of azobisisobutyronitrile, 12.5 g of polyvinylpyrrolidone, and 500 mL of anhydrous ethanol, sonicate for 10 min to fully dissolve into a homogeneous solution, purge with nitrogen to remove oxygen, and rotary evaporate in a 70 °C constant temperature water bath for 12 h. After settling, discard the supernatant, wash the precipitate three times with anhydrous ethanol, and then wash three times with water. The resulting substance is seed microspheres, which are dispersed in an 8% polyvinyl alcohol aqueous solution at 0.1 g / mL to obtain the seed microsphere slurry.

[0038] The specific construction method for trenchless repair of sewer pipes using this light-cured inner lining flexible hose is as follows:

[0039] Before construction, ensure the safety of the construction site and block water flow upstream and downstream. Then, dredge and clean the pipes, pre-treat the existing pipes to ensure no debris remains, prepare all items and tools for the construction site, and check the equipment to ensure all functions are working properly.

[0040] Pull in the protective film, ensuring it is not twisted, and secure it tightly to the bottom of the initial inspection well. Pull in the UV-cured liner hose and attach cable ties to both ends.

[0041] Turn on the air compressor and allow the UV-curing liner hose to slowly expand. Insert the UV lamp holder through the air lock (Caution: Do not damage the inner lining). Continue inflating until the specified pressure is reached. Pull the lamp holder while simultaneously observing the inside of the hose through the curing equipment display (no damage, bending, or wrinkles). Turn on the UV lamp and set the lamp holder's movement parameters according to the manual. The lamp holder's movement is the material curing process. After curing, maintain airflow for 10 minutes for cooling. Turn off the blower, remove the end cap and UV lamp holder, cut the ends, and inspect the cured pipe using CCTV.

[0042] Example 2: The only difference between this example and Example 1 is that the light-curing glass fiber resin layer is made by brushing light-curing resin onto both sides of glass fiber cloth, with the same amount of coating on both sides, and the total amount of coating is 42% of the weight of the glass fiber cloth.

[0043] Example 3: The only difference between this example and Example 1 is that the light-curing glass fiber resin layer is made by brushing light-curing resin onto both sides of glass fiber cloth, with the same amount of coating on both sides, and the total amount of coating is 48% of the weight of the glass fiber cloth.

[0044] Example 4: The only difference between this example and Example 1 is that the photocurable resin, by weight, includes the following raw material components: 100 parts epoxy acrylate, 12 parts porous microspheres, 35 parts diluent, 5 parts ultraviolet photoinitiator, 2 parts thickener and 0.8 parts defoamer.

[0045] Example 5: The only difference between this example and Example 1 is that the photocurable resin, by weight, includes the following raw material components: 100 parts epoxy acrylate, 15 parts porous microspheres, 45 parts diluent, 9 parts ultraviolet photoinitiator, 4 parts thickener and 2 parts defoamer.

[0046] Example 6: The only difference between this example and Example 1 is that the photocurable resin, by weight, includes the following raw material components: 100 parts epoxy acrylate, 13 parts porous microspheres, 42 parts diluent, 6 parts ultraviolet photoinitiator, 2.5 parts thickener and 1 part defoamer.

[0047] Comparative Example 1: The only difference between this comparative example and Example 1 is that the glass fiber cloth is specifically the uniaxial product EKB400(0 / 90)-1270.

[0048] Comparative Example 2: The only difference between this comparative example and Example 1 is that the glass fiber cloth is specifically the four-axis product EKB600(0 / 45 / 90 / -45)-1270.

[0049] Comparative Example 3: The only difference between this comparative example and Example 1 is that the glass fiber cloth is replaced with chopped glass fiber.

[0050] Specifically, the light-curing glass fiber resin layer is made by mixing chopped glass fibers and light-curing resin, with the light-curing resin accounting for 45% of the weight of the chopped glass fibers.

[0051] Comparative Example 4: The only difference between this comparative example and Example 1 is that the porous microspheres are replaced with seed microspheres in the preparation of the photocurable resin.

[0052] Specifically, the preparation method of seed microspheres is as follows: 50 mL of glycidyl methacrylate, 0.25 g of azobisisobutyronitrile, 12.5 g of polyvinylpyrrolidone and 500 mL of anhydrous ethanol are mixed and sonicated for 10 min to fully dissolve into a homogeneous solution. Nitrogen gas is passed through to remove oxygen, and the mixture is rotary evaporated in a constant temperature water bath at 70℃ for 12 h. After settling, the supernatant is discarded, and the precipitate is washed three times with anhydrous ethanol and then washed three times with water to obtain seed microspheres.

[0053] Comparative Example 5: The only difference between this comparative example and Example 1 is that the porous microspheres were removed in the preparation of the photocurable resin.

[0054] The photocurable resin comprises the following raw material components by weight: 100 parts epoxy acrylate, 40 parts diluent, 7 parts ultraviolet photoinitiator, 3 parts thickener and 1.5 parts defoamer.

[0055] Comparative Example 6: The only difference between this comparative example and Example 1 is that the glass fiber cloth is replaced with chopped glass fiber; and the porous microspheres are removed in the preparation of the photocurable resin.

[0056] Test example: Test subjects: hoses prepared in Examples 1-6 and Comparative Examples 1-6.

[0057] Test items and basis: 1. Surface flatness after curing - visually inspect the surface of the cured hose for wrinkles and record the number of wrinkles;

[0058] 2. Bending strength - GB / T 1449-2005;

[0059] 3. Tensile strength - GB / T1447-2005.

[0060]

[0061] Results Analysis: Analyze Examples 1-6 and combine the data in Table 1 and... Figure 1-2 It can be seen that the photocurable liner hose prepared by the present invention has excellent surface smoothness and no wrinkles after curing, and excellent mechanical properties (flexural strength and tensile strength).

[0062] Analysis of Example 1 and Comparative Examples 1-3, combined with data from Table 1 and Figure 1-2It can be seen that in the preparation of photocurable glass fiber resin layers, using glass fiber cloth is more beneficial to improving the surface smoothness and mechanical properties (flexural strength and tensile strength) of the hose than using chopped glass fiber. Among them, biaxial glass cloth has the best improvement effect, which is significantly better than uniaxial glass cloth and tetraaxial glass cloth.

[0063] Analysis of Example 1 and Comparative Examples 4-5, combined with data from Table 1 and Figure 1-2 It can be seen that in the preparation of photocurable glass fiber resin layers, the addition of seed microspheres, a raw material component of photocurable resin, can improve the surface smoothness and mechanical properties (flexural strength and tensile strength) of the hose. Furthermore, by cross-linking the seed microspheres into porous microspheres for use, the surface smoothness and mechanical properties (flexural strength and tensile strength) of the hose can be further improved.

[0064] Analysis of Example 1 and Comparative Examples 3, 5 and 6, combined with data from Table 1 and Figure 1-2 It can be seen that in the preparation of photocurable glass fiber resin layer, glass fiber cloth and porous microspheres can work together to improve the surface smoothness and mechanical properties (flexural strength and tensile strength) of the hose.

[0065] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0066] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing a photocurable inner liner hose, comprising sequentially bonding a light-transmitting inner film, a photocurable glass fiber resin layer, and an anti-ultraviolet outer film from the inside out to obtain a photocurable inner liner hose, characterized in that, The photocurable glass fiber resin layer is made by brushing photocurable resin onto both sides of glass fiber cloth, with the same amount of coating on both sides, and the total coating amount is 42%-48% of the weight of glass fiber cloth; the photocurable resin, by weight, includes the following raw material components: 100 parts epoxy acrylate, 12-15 parts porous microspheres, 35-45 parts diluent, 5-9 parts ultraviolet photoinitiator, 2-4 parts thickener, and 0.8-2 parts defoamer; The method for preparing the porous microspheres is as follows: A1. Dissolve 20 mL of glycidyl methacrylate, 15 mL of ethylene glycol dimethacrylate, 20 mL of toluene, 40 mL of n-octanol and 0.8 g of benzoyl peroxide by sonication. Add 500 mL of an aqueous solution containing 0.2% polyvinyl alcohol and 0.05% sodium dodecyl sulfate. Sonicate to completely emulsify the oil phase to obtain an emulsion. A2. Disperse 100 mL of seed microsphere slurry in 500 mL of an aqueous solution containing 1% polyvinyl alcohol and 0.1% sodium dodecyl sulfate to obtain a seed dispersion. A3. The emulsion obtained in A1 was added dropwise to the seed dispersion obtained in A2 at a rate of 10 mL / min. The temperature was controlled at 35℃, and the mixture swelled for 12 hours. Nitrogen gas was purged for 20 min, and the mixture was stirred at a constant temperature of 70℃ for 24 hours to obtain porous microspheres. In A2, the preparation method of the seed microsphere slurry is as follows: Mix 50 mL of glycidyl methacrylate, 0.25 g of azobisisobutyronitrile, 12.5 g of polyvinylpyrrolidone, and 500 mL of anhydrous ethanol, sonicate for 10 min to fully dissolve into a homogeneous solution, purge with nitrogen to remove oxygen, and rotary evaporate in a 70 °C constant temperature water bath for 12 h. After settling, discard the supernatant, wash the precipitate three times with anhydrous ethanol, and then wash three times with water. Disperse the resulting substance at 0.1 g / mL in an 8% polyvinyl alcohol aqueous solution to obtain the seed microsphere slurry.

2. The method for preparing the photocurable inner liner hose according to claim 1, characterized in that, The fiberglass cloth is a biaxial fabric.

3. The method for preparing the photocurable inner liner hose according to claim 1, characterized in that, The epoxy acrylates include phenolic epoxy acrylates and / or bisphenol A epoxy acrylates.

4. The method for preparing the photocurable inner liner hose according to claim 1, characterized in that, The diluent includes 1,6-hexanediol diacrylate and / or trimethylolpropane triacrylate.

5. The method for preparing the photocurable inner liner hose according to claim 1, characterized in that, The ultraviolet photoinitiator includes 1-hydroxycyclohexylbenzophenone and / or 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

6. The method for preparing the photocurable inner liner hose according to claim 1, characterized in that, The thickener is gaseous SiO2.

7. The method for preparing the photocurable inner liner hose according to claim 1, characterized in that, The defoamer is polydimethylsiloxane and / or polyether.

8. A light-curing inner liner hose, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.

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